Pulse receiving and repeating system



Feb. 22, 1949. c. M. THEILLAUMAS 2,462,144

' PULSE RECEIVING AND REPEATING SYSTEM Filed April 12, 1946 I N V EN T0R. CLEMENT IZ THEILZAUYYAS BYWM/A ATTORNEY.

Patented Feb. 22, 1949 PULSE RECEIVING AND REPEATING SYSTEM Clement M.Theillaumas, Boulogne-Billancourt, France, assignor to Interna ionalS'andard Electric Ccrporaiion, New York, N. Y., a corporation ofDelaware Application April 12. 1946, Serial No. 661,493

In France March 27, 1945 Section 1, Public Law 690, August 8, 1946Patent expires March 27, 1965 6 Claims.

This invention relates to improvements in pulse receiving and repeatingsystems for telecomunication networks using, for example, socalledcommercial frequency currents for signaling. Such a system, which mayalso be adapted directly to voice-frequency signaling purposes by simplemodification of the features of construction of some of its circuitelements, is disclosed in my co-pending application Serial N0. 660,269,filed April 6, 1946.

In the pulse receiving and repeating system described in my co-pendingapplication, detection of the incoming signal is effectedv by means of aspace discharge tube preferably of the coldcathode type, and pulserepetition is assured through a relay arrangement in the tube platecircuit. The moment of beginning of a pulse is determined by theionization or lighting-up of the cold-cathode tube which causes theinitial energization of a relay. The falling-back of this relay and notthe inactivation of the tube determines the end of the pulse train. Anauxiliary relay which is caused to be energized by the operation of thefirst relay effects the inactivation of the tube and also theapplication to the out-., going line of thecurrent source used toretransmit a signaling pulse train.

For each signaling direction, the pulse-repeating or receiving devicecomprises a cold-cathode tube fed from the input line through acondensertransformer series circuit and employs a relay arrangementcomprising a two-winding retransmitting anode-relay, an auxiliary relayfor internal switching, and a slow relay for neutralizing the signalinput equipment of the other channel; One of the windings of saidanode-relay is energized by signaling current from the input line bymeans of a rectifier for holding this relay actuated during the periodof the incoming signal.

An object of the present invention is to pro-'- vide, in a system of thetype'described, additional means for assuring high sensitivity andoperating dependability.

Another object of this invention is to provide, in a system of the typedescribed, high-fidelity definition of the duration of a retransmittedpulse train.

A further object of the present invention is to adapt a system of thetype described to the employment of ordinary switching relays common inautomatic telephony, eliminating the need for slug-fitted relays of theslow-releasing type.

According-to one feature of the invention, retransmission of therepeated signal to the incoming line is prevented by the operation of a.

2 relay contact. According to another feature, the outgoing line isconnected to a discharge circuit after the signaling process has beencompleted.

An example of a circuit illustrating this invention is shown by thesingle figureof the accompanying drawing, the description of which is asfollows:

A commercial-frequency or other signal current coming from the eastionizes the cold-cathode tube TE between cathode 9 and auxiliaryelectrode 9st through booster-transformer 4 ove the following circuit:

I Wire a from one side of the east input line E to back contacts I ofACE and 2 of COR, condenser 3, primary winding of transformer 4, backcontacts 5 of ACE and wire I) to the other side of the east input line.

An incoming signal from the east side input line thus produces adischarge between anode and cathode of TE, and relay AER operates. Thisrelay is energized by current from high tension battery 6 through itsright-hand Winding, back contact 1 of auxiliary relay BER, anode 8 andcathode 9 of tube TE, and ground [0.

Relays BER and CER are each equipped with double front contacts. Theserelays are actuated following the operation of the relay AER closing itsfront contacts l2 and I3. BER is energized by current through itswinding from 24 volt battery ll, front contact l2 of AER and ground I5;and CER by current through its winding from 24 volt battery l4, frontcontact l3 of AER and ground l5.

Through another double front'contact l6--l| on AER, condenser 3 inseries with the primary through the rectifier I9 to keep relay AERoperated.

The west side input line W connection with the pulse repeating apparatusis broken through the two reversing contacts 25-2'l of AER and a 50-cycle local source of ringing current S is connected by wires 0 and d tothe outgoing west side line for retransmission.

Alternating or pulsating signal current from the east input line issupplied to rectifier l9 which in turn supplies current to the left-handwinding of AER for holding this relay operated during a signalingperiod. The circuit for the alternating current from the line is, wirea, back contact I of ACE, back contact 2 of COR, front contact E6 ofAER, rectifier bridge l9, primary winding of transformer 4, back contactof ACE, wire b; and rectified current from rectifier I9 then energizesthe left-hand holding winding of AER as stated above.

Relays BER and GER have been energized by the closing of contacts i2l3on AER. Relay BER upon being energized breaks the plate circuit of tubeTE at its contact 1 and grounds the control electrode 9:1: at itsfrontcontact 2|. Relay CER. upon being energized short-circuits its lowresistance left-hand Winding through a front contact 23 which makes itslow to fall back and allows it to hold during a pulse train. Throughtwo other front contacts 24, 28, it short-circuits the mid-points of thedifferential transformers 20 terminating the respective east and Westside transmission lines. This inactivates the respective grid circuitsof the amplifiers which serve as a coupling between the two channels.Finally, through a reversing contact 22, CER breaks the west-side inputcircuit at anadditional point and prepares a line-discharge circuit forthe westside transmission channel.

When the incoming signal ceases, relay AER falls back, as the rectifiedsignal current flowing through the left-hand holding winding of therelay ceases, and disconnects the supply of current energizing relaysBER at 12 and CER at I3. Relay BER is slightly delayed in falling backby a rectifier cell 26 shunting a fraction of its winding-while relayCER is much longer delayed in opening its front contacts. During thetime elapsing between the falling back of AER and that of GER, thewest-side line is discharged over the circuit comprising wire 0, backcontact 21 of AER, front contact 22 of CER, BOO-ohm resistance and wire11. After the falling back of CER, the device is ready to receive andretransmit a new pulse.

Main relay AER, auxiliary relay BER and slow blocking relay CE'R operatein sequence as their respective windings are energized; and as theirrespective windings are deenergized their armatures fall back insuccessive sequence with suitable time delays as pointed out above inthe description of the'circuits in which they operate.

As auxiliary relay BER operates with a slight delay retransmission iscorrected to a certain degree for an accidentally short incoming signal.A perfect correction is not necessary here because of the fact that acold-cathode tube operates under theactionof a very brief signal. Thedelay obtained is equal to the time required for good operation of endreceivers.

The operation of the repeater for a west-side incoming signal is similarand consequently need not be described in detail.

The limits of use of the system in a practical operating example are asfollows:

The alternating or pulsating pulse signal, on arrival must have avoltage greater than or equal to '12 volts, the optimum desired voltageis 18 volts 6 volts; the tube supply voltage is 130 volts 15 volts withthe possibility of using a lower voltage by simply changing aresistance; in the case of a 4-wire terminating set system, for example,by the joint use of the 48 volt battery and the +70 volt battery.

The auxiliary relay and the slow relay are fed under 24 volts withpossibility of feeding under 48 volts by the mere addition of aresistance.

While I have shown and described a particular embodiment of myinvention, it will be apparent to those skilled in the art thatvariations and. modifications thereof may be made without departing fromthe underlying principles of the invention. I, therefore, desire thefollowing claims to include within the scope of my invention all suchsubstitutions and variations whereby substantially the results of myinvention may be obtained by the use of substantially the same orequivalent means.

What is claimed is:

1. A pulse receiving system for telecommunication networks comprising acold-cathode tube, a transformer having its secondary connected to theinput of said tube and its primary arranged to receive an incomingsignal, a relay having a winding connected in the anode circuit of saidtube, a rectifier bridge having a pair of opposite junction pointsconnected across a winding of said relay, and normally open relaycontacts connected in series with the other pair of junction points ofsaid bridge, arranged to connect said other pair of points across thesignal input upon ionization of said tube.

2. A pulse receiving system for telecommunication networks comprising acold-cathode tube, a transformer having its secondary connected to theinput of said tube and its primary arranged to receive an incomingsignal in series with a condenser, a two-winding relay having a firstwinding connected in the anode circuit of said tube, a rectifier bridgehaving a pair of opposite junction points connected across the secondwinding of. said relay, front contacts associated with said relay andconnected in series with the other pair of junction points of saidbridge, arranged to connect said other pair of junction points in shuntwith said condenser and part of said primary winding, and means forbreaking the anode circuit of said first relay winding subsequent toionization of said tube.

3. A pulse receiving system for telecommunication networks comprising,in combination, a cold cathode tube, a transformer having its secondaryconnected to the input of said tube and its primary arranged to receivean incoming signal, a condenser in series with said primary, atwowinding'anode-relay having a winding connected to the tube anode andenergized upon activation of said tube, a rectifier bridge having a pairof opposite junction points connected across a winding of saidanode-relay, front contacts of said anode-relay connected to the otherpair of Junetion points of said bridge in shunt with said condenser andpart of said primary winding, an auxiliary relay having a windingconnected in series with front contacts of said anode-relay and a sourceof energy arranged to energize said auxiliary relay, said auxiliaryrelay having back contacts connected in the anode circuit of saidanode-relay, and front contacts and a circuit connecting the latterfront contacts across the input of the tube, arranged to short circuitsaid input when the auxiliary relay is energized.

4. A pulse receiving system for telecommunication networks comprising incombination a cold cathode tube, means for impressing an incoming si nalupon said tube and thereby causing ionization thereof, a first relay,means for energizing the first relay when said tube is in operation,

means for maintaining said first relay in operation after the tubeoperation is terminated, a second relay, means for energizing the secondrelay when the first relay is energized, means including a back contactof the second relay for terminating the operation of the tube when thecircuit relay is energized, means for maintaining said second relay inenergized condition after release of the first relay, a third relay,means for energizing the third'relay when the first relay is energized,a signal output circuit, means including a back contact of the thirdrelay for rendering the output circuit inoperative when the third relayis energized, and means for maintaining the third relay in energizedcondition after release of said first and second relays.

5. A pulse receiving system for telecommunication networks comprising acold cathode tube, two transmission channel circuits each terminated bya differential transformer, means for impressing an incoming signal uponsaid tube and thereby ionizing the tube, a first relay, means forenergizing the first relay when the tube is in operation, means formaintaining said relay in energized condition for the duration of thesignal, a second relay, means for energizing the second relay when thefirst relay is energized, means including a back contact of the secondrelay for terminating the operation of said tube when the second relayis energized, a third relay, means for energizing the third relay whenthe first relay is energized, means including a back contact of thethird relay for disconnecting the outgoing transmission channel, andswitching means operated by energization of said first relay for shortcircuiting the respective mid-points of said difierential transformers.

6. A pulse receiving system for telecommunication networks comprising acold cathode tube, two transmission channels, a differential transformerterminating each channel, means for impressing an incoming signal uponsaid tube and thereby ionizing the tube, a first relay, means forenergizing the first relay when said tube is in operation, a secondrelay, means operative when the first relay is energized for placingsaid tube out of operation, means for delaying the release of the secondrelay after release of the first r lay, a third relay, means operativewhen the first relay is energized and including a back contact of thethird relay for disconnecting the outgoing channel, means includingfront contacts of said third relay for short circuiting the respectivemidpoints of said differential transformers and means for delaying therelease of said third relay after the release of said first and secondrelays.

CLEIVIENT M. THEILLAUMAS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,070,900 Harris Feb. 16, 19372,222,248 Blount Nov. 19, 1940

